Television-facsimile system



Aug. 20, 1940. P. c. GOLDMARK 2,211,926

' TELEVISION-FACSIMILE SYSTEM Filed Nov. 10, 1936 4 sheets-sue; 2

INVENTOR.

mbizzom in? x M00.

S- 20, 1940- n P. c. GQLDMARK 2,211,926

' TELEVISION-FACSIMILE sYsTEM Filed Nov. 10,. 1956 4 Sheets-Sheet s.

' per W 79 INVENTOR;

I Qwwaw- Patented Aug. 20, 1940 2,211,926 TELEVISION-FACSIMILE. SY'ISTEM Peter C. Goldmark, New York, N. Y., assignor to.

Markia Corporation, New York, N. Y., a corporation of New York Application November 10, 1936, Serial No. 110,066

15 Claims.

This invention relates to radio communicating systems which have facsimile reproducing means,

and more particularly to radio transmitting and receiving systems which send both television and ordinary sound signals, when combined with facsimile transmitting and reproducing devices of a character which make records of pictures, news dispatches, and the like.

The invention has for its object generally the provision of radio communication systems with simple and convenient means whereby such systems may additionally.- send and receive facsimile reproductions and their range of usefulness is correspondingly increased.

More specifically, the object of the invention is to provide radio communicating apparatus with facsimile communicating means of a char-, acter which may be used in conjunction with standard equipment and is adapted for making 59 permanent pictures, news' dispatches, and the like, that may be later inspected.

Another object is to provide suitable circuit Still another object is to provide means for extending the usefulness of ordinary radio receivers 3 by the provision of suitable additional equipment that may be incorporated in standard equipment and permanent records of pictures, news dispatches, and the like, readily made.

Other objects of the invention will in part be obviousand will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, which will be exem- 40 plifled in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the'nature and objects of the invention," reference should be had 45 to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of a radio transmitting system adapted for the transmission of 6 both sound and television .signals and provided with facsimile transmitting means, in accordanc with the invention:

Fig. 2 is a diagrammatic view of a radio receiving system adapted for the reception of signals 55 sent by apparatus such as shown in Fig; 1, and

includes facsimile reproducing means for the practice of the invention;

Fig. 3 is a diagrammatic view similar to Fig. 1, showing a modification in which the facsimile transmitting means are associated solely with the 5 television transmitting stages;

Fig. 4 is a diagrammatic view similar to Fig. 2,

but showing a modified form of receiving system particularly adapted for the reception of signals when transmitted by apparatus provided -as 10 shown in Fig. 3; 1

Fig. 5 shows still another modification of the transmitting apparatus shown in Fig. 1, whereby the simultaneous transmission of sound, television and facsimile signals may be achieved; 15

Fig. 5a. is an explanatory diagram; Fig. 6 shows diagrammatically another modified-form of receiving system adapted for the simultan'eous .reception -of sound, television and facsimile signals, when transmitted by apparatus such as shown in Fig. 5; and

Fig. '7 shows a still further modified form of receiving system in which provision is made for receiving an ordinary broadcast sound signal band, as well as the bands of television and facsimile signals.

Radio communicating systems which are de signed for the transmission and reception of television, and ordinary broadcast sound signals require in general the provision of separate sets of amplifying, modulating, detecting, and reproducing stages for the sound and television effects. Receiving sets intended for this service are, in consequence, relatively complicated and relatively costly. O'ne purpose of the invention is to make radio communicating systems of the character indicated adapted for another service by the provision'of a relatively small amount of additional equipment, employing existing equipment as far as practical, and involving the expenditure of only a relatively small sum. To this end, the means for making the facsimile reproduction is, combined with both the transmitting and re-- ceiving sets in such a way that the carrier wave for theradlo signals also operate them. Such 5 means may hence be operated concurrentlywith the reception of either ordinary sound or television signals, or of both, or during periods when p the system is not otherwise actively employed,

for example, during the night hours after midnients, by printing a series of dots on suitable material, such as plain paper, although chemicaloperated by signal impulses that are selected by suitable filter means from the regular signal carrier. Accordingly, at the transmitting end, the facsimile signal is superposed upon either the sound or the television carrier as an additional modulating impulse.

Referring now to the drawings, and'particularly to Fig. 1, separate sets of stages for sound and television are shown, and are in cooperative association. Here, ||l denotes a microphone which is connected through an amplifying stage II to a modulating stage I2, and thence through a radio frequency stage |3 with a broadcast radiating antenna I4. The set of television stages comprises a camera |5 adapted to pick up light from any scene to be televised and translated it into electric impulses which are transmitted to a vision amplifying stage It. This latter is connected to a modulating stage I1 and a radio frequency stage IB of relatively high frequency that has a radiating antenna IS. A generator 20 of a synchronizing signal is connected to the television transmitting system and has a pair of conductors 21 leading off to supply actuating current to the facsimile transmitting device. Any suitable source of actuating current, however, may be employed, but it is generally convenient to employ the synchronizing impulse as the actuating current.

The facsimile reproducing means here illustrated as employed, while not the only form that may be used, is a convenient form and is used in what is known as the Young system. As here illustrated, the transmitting device comprises a rotating cylinder 2| on which is fastened a copy of the material whose facsimile is to be reproduced at the receiving end. This cylinder is driven by a synchronous motor 22 actuated by impulses supplied through the conductors 2'1. Continuous line scanning is here employed; hence, a source of light is shown at 23, the refiections of which from the material to be transmitted being arranged to be picked up by a suitable optical system (not shown in the interests of clearness of illustration in the drawings) and projected into a photocell 24, whose current may be suitably amplified by an amplifying stage at 25 and converted into desired signal impulses by suitable means, for example, a chopping device, the resulting impulses being impressed by way of conductors 26.0n the input of the modulator l2. In such arrangement, provision is made to have the facsimile signal superposed upon the carrier generated at |2 only when sound signals are not being broadcast. To this end, dis connecting switchesare shown in the conductors 26 and 21 and in the connections between stages II and I2. By means of these switches the microphone may be disconnected when the facsimile motor 22 and amplifier 25 are in operation, and vice versa.

For the reception of signals broadcast by the system shown in Fig. 1, a receiver of the character shown in Fig. 2 may be provided. Here, an antenna 30 is designed topic up signal energy and supply the same to a radio frequency amplifying stage 3|. Sound signal detecting andamplifying stages are shown respectively at 32 and connections 41.

33, together with a loudspeaker at 34, while similar stages for television reproduction are shown at 35 and 36, together with a cathode ray receiving tube at 31. A synchronizer for the receiving tube 31 is shown at 38. The stages 32 and 35 are shown as coupled to the stage 3| through coupled coils 39-39 and 40-40. By properly tuning these couplers, the combined sound and television signals may be separated into components whichrtraverse the sound and television reproducing stages separately.

Here, the facsimile reproducing device is shown as an anvil cylinder 4| rotated by means of a synchronous motor 42 that is connected to be actuated by a suitable source of electrical impulses, here shown as supplied from the syn.

chronizing oscillator 38 by the conductors 43. Here, also an electromagnetic reciprocating means 44 is provided for actuating a printing bar 45 that cooperates with a second or curved bar 48 disposed on and rotating with the cylinder 4|. The reciprocating means 44 has electrical connections at 41 through which it may be connected in parallel with the loudspeaker 34, a disconnecting switch 48 being interposed in the Thus, when the speaker is in operation, the facsimile reproducing device is inoperative, and vice versa. In this arrangement, it is seen'that when a piece of paper, in

contact with the carbon side of a sheet of carbon paper, is fed between the bars 45 and 46, a succession of dots will be made on the Paper that will reproduce one line element of the picture material on the cylinder 2| with each revolution of the cylinder at 4|.

In Fig. 3 there is shown a modified form of transmitting system in which the sound equipment comprises a microphone, amplifying and modulating stages, together with antenna, arranged as shown in Fig. 1, except that no facsimile transmitting device is indicated as in association. Instead, the facsimile transmitting device is connected to apply its modulating effect entirely to the television carrier. Here, the television system is shown as comprising a camera l5 and stages l6, l1, and |8, together with an antenna l9, as in Fig. 1. A synchronizing oscillator is shown at 20 which supplies the synchronizing oscillations to the modulator I! and also, through switches 21, to the synchronous motor 22 for rotating a cylinder 2| that is scanned by a photoelectric cell 24 whose current is converted into suitably amplified impulses by a I stage at 25 that is connected by conductors 26 to modulate the television .carrier when in operation. Switches 26' are interposed in these conductors for disconnecting the facsimile reproducing device when desired, the switches 26 and 21 being closed only when the switches 21", for disconnecting the camera |5,,are open.

In Fig. 4, a modified form of receiving system is provided which has the facsimile reproducing device associated entirely with the television stages and is thus adapted for the reception of signals transmitted by means of the system shown in Fig. 3. Here, an antenna 5|] collects signal energy and amplifies it in stage 5|, there being sep'arate sets of stages for detecting, amplifying and reproducing the sound and television signals separately, the sound set being shown as comprising stages 52, 53 and 54, while the television set comprises stages 55, 56, and 51; a synchronizer being shown at 58. Thned coupling coils 59-59 and Gilare provided respectively be- 76 .prises a cylinder 6| driven by a synchronous motor 62 that is connected by conductors 63 with the synchronizer 58. An electromagnetic actuator 64 has a bar 65 which it reciprocates in cooperation with a curved bar 66 on the cylinder 6!. Current to actuate the actuator 64 is supplied by conductors 61 which lead to the cathode ray supply conductors and through which the facsimile signal current passes. In these conductors, switches 68 are interposed which are normally open when a television signal is being received but are closed when it is desired to operate the facsimile reproducing device.

In Fig. 5, another modified form of transmitting system is shown, where the parts are arranged so as to permit the concurrent transmission of sound, television, and facsimile signals. Here, as in Fig. 1, a microphone is shown at IU, coupled through amplifying and modulating stages to the broadcast radiating antenna Hi. The television transmitting stages are also shown arranged as in Fig. 1, and comprise a camera 15, which is coupled through amplifying and modulating stages to the radiating antenna IS. A synchronizing oscillator is shown at 20 coupled to impress synchronizing impulses upon the television signal.

The-facsimile transmitting device associated with these transmitting stages is here shown as in Fig. 1 and comprises a cylinder 2|, motor 22, light source 23, photo-cell 24, and amplifying stage 25. In order that the amplified photoelectric current may be the more readily associated with the sound signals for broadcasting, a modulator 25' is provided for superposing the facsimile signals upon a. subcarrier generated thereby, subcarrier for such superposed facsimile signals being preferably immediately adjacent to the upper frequencies of the sound signals. By this arrangement, it is seen that the facsimile signal may be broadcast at the same time that the sound signal is being broadcast, and on the same main carrier, the facsimile subcarrier side bands being preferably somewhat beyond the sound signal side bands, as shown in Fig. 5a, and television signals being simultaneously broadcast on their own carrier.

In Fig. 6, a receiving system is shown, which is specifically adapted to pick up and reproduce the sound, television, and facsimile signals transmitted by the apparatus shown in Fig. 5. Here, an antenna-191s arranged to pick up signal energy and amplify the same in a stage H with which is coupled a heterodyning stage 12 which changes the incoming frequencies to intermediate frequencies which are separated by the coupled coils 13--'|3' and |4|4' so as to traverse separate sound and television amplifying paths, the facsimile signal going with the sound signal which is detectedat l5, amplified at I5, and is then led by the output circuit 15 to. actuate the loudspeaker H. A tuned coil 19 in the output'circuit of the amplifier 15' is arranged to select the facsimile subcarrier and supply it to the detector 84 for reproduction'of the facsimile signal in the facsimile reproducing device, here shown as comprising an actuator 8.4, a bar 85, and a cylinder 8| rotated by means of a synchronous motor 82 that is supplied with current from the synchronizer 80 that. is associated with the television detecting and amplifying stage I9; this latter being coupled to the coil 14'.

The operation of the facsimile reproducing apparatus is similar to that described in connection with Fig. 2. The television reproducing cathode ray tube is shown at 81 coupled to the stage 19 and to the synchronizer 80.

In Fig. 7 is shown still anothermodification of a. receiving system adapted for the reception concurrently of sound, television, and facsimile signals, this set being arranged specifically for the reproduction of sound signals from an ordinarybroadcast band, or from a plurality of such bands, as well as from ultra short wave bands. Here, an antenna for collecting signal energy is shown at 90 and has an ordinary broadcast band radio frequency amplifying stage 9| connected through a conductor 9i. In parallel with stage 9| is connected a separate ultra short wave amplifying stage 92 for signals of the. type transmitted by the apparatus of Fig. 5. To stage 9| is connected a heterodyning stage 93 and sound detecting and amplifying stages 94 for supplying a loudspeaker 95. To stage 92 in the ultra short wave set is connected a heterodyning stage 96 that passes intermediate frequencies that carry the facsimile, sound, and television signals. Stage 96 is coupled by tuned couplers 9T--91' and 98-98 to supply separately the sound detecting and amplifying stage 99 and the television detecting and amplifying stage I with sound and facsimile signals, and with television signals, respectively. From the sound intermedi: ate frequency and audio amplifying stage 99 leads a ,coupling circuit having a portion Hll arranged as a low-pass filter adapted to pass any frequency below that of the facsimile subcarrier and has coupling connections to feed such frequency into the loudspeaker 95. There is a second portion H12, in series with portion IOI, that is tuned to pass the facsimile subcarrier, a detector I03 and an electromagnetic actuator 13' for the facsimile reproducing device being coupled to portion I02 to receive the facsimile signal. This actuator reciprocates a bar I that cooperates with a curved bar I06 on a rotating cylinder II I; this cylinder being rotated by means of a synchronous motor H2 and supplied with current from a synchronizing oscillator H3. This latter is associated with an amplifying stage H4 cascaded upon the stage I90 that supplies the television signal to the cathode ray tube i I5. In this arrangement, sound, television, and facsimile signals may not only be reproduced simultaneously, but sound signals from the ordinary broadcast bands may also be received and reproduced in the speaker 95 by simply connecting the amplifying stages for the ordinary broadcast circuit to the antenna by closing the switch in conductor 9 v The mode of operation of the several features is believed to be suificiently explained in connection with the description of each of the above figures of the drawings or will be obvious therefrom.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and d'esireto secure by Letters'Patent is:

1. In apparatus for radio communication,.' the combination at a transmitting station which comprises a first transmitting set, including a first modulator, adapted to transmit a sound-signalmodulated carrier, a second transmitting set, including a second modulator, adapted to transmit a television-signal-modulated carrier, a sound signal generator for supplying signal energy to said first modulator, a television signal generator for supplying signal energy to said second modulator, a facsimile signal generator for supplying signal energy to one of said modulators, said facsimile signal generator including an actuated element with which a corresponding element at a facsimile receiver is desired to be synchronized, a source of synchronizing impulses arranged to supply synchronizing impulses to said second transmitting set, means for coupling said television signal generator to said source to correlate the synchronizing impulses with the television signals, and-means for coupling said facsimile signal generator to said source to maintain a synchronous relationship between the synchronizing impulses and the said actuated element.

2. In apparatus for radio communication, the combination which comprises a first transmitting set, including a first modulator, adapted to transmit a sound-signal-modulated carrier, a second transmitting set, including a second modulator, adapted to transmit a television-signal-modulated carrier, a sound signal generator, means for supplying signals from said sound signal generator to said first modulator, a television signal generator, means for supplying signals from said television signal generator to said second modulator, a generator for generating facsimile signals, means for generating a subcarrier, means for modulating said subcarrier with said facsimile signals, and means for supplying said facsimile-signal-modulated subcarrier to said first modulator, said subcarrier as modulated being substantially outside of the frequency band of the sound signals.

3. In apparatus for radio communication, the combination which comprises a first transmitting set, including a first modulator, adapted to transmit a sound-signal-modulated carrier, a second transmitting set, including a second modulator, adapted to transmit a television-signaLmodulated carrier, a sound signal generator, means for supplying signals from said sound signal generator to said first modulator, a television signal generator, means for supplying signals from said television signal generator to said second modulator, a facsimile signal generator including an actuated element with which a corresponding element at a facsimile receiver is desired to be synchronized, means for supplying signals from said facsimile signal generator to said first modulator, a source of synchronizing signals arranged to supply synchronizing impulses to said second transmitting set, means for coupling said television signal generator to said source to correlate the synchronizing impulses with the television signals, and means for coupling said facsimile signal generator to said source to maintain a synchronous relationship between the synchronizing impulses and the said actuated element.

4. In apparatus for radio communication, the combination which comprises a first transmitting set, including a first modulator, adapted to transmit a sound-signal-modulated carrier, a second transmitting set, including a second modulator, adapted to transmit a television-signal-modulated carrier, a sound signal generator, means for supplying signals irom said sound signal generator to said first modulator, a television si nal generator, means for supplying signals from said television signal generator to said second modulator, a

generator for generating facsimile signals including an actuated element with which a corresponding element at a facsimile receiver is desired to .be synchronized, means for generating a subcarrier, means for modulating said subcarrier with said facsimile signals, means for supplying said facsimile-signal-modulated subcarrier to said first modulator, said subcarrier as modulated being substantially outside of the frequency band of the sound signals, a source of synchronizing signals arranged to supply synchronizing impulses to said second transmitting set, means for coupling said television signal generator to said source to correlate the synchronizing impulses with the television signals, and means for coupling said facsimile signal generator to said source to maintain a synchronous relationship between the synchronizing impulses and the said actuated element.

5. In apparatus for radio communication, the combination which coinprises a first transmitting set, including a first modulator, adapted to transmit a sound-signal-modulated carrier, a second transmitting set, including a second modulator,

adapted to transmit a television-signal-modulated carrier, 2, sound signal generator, means for supplying signals from said sound signal generator to said first modulator, a television signal generator, means for supplying signals from said television signal generator to said second modulator, a generator for generating facsimile signals, including a rotatable cylinder and a synchronous motor to drive said cylinder, for supplying signal energy to said first modulator, a source of synchronizing impulses arranged to supply synchronizing impulses to said second transmitting set, means for connecting said source to the facsimile signal generator to provide driving energy for said synchronous motor, and means for coupling said source to said television-signal generator to correlate thesynchronizing impulses with the television signals;

6. In the art of radio communication, the method of simultaneously transmitting television signals, sound signals and facsimile signals which comprises providing a first carrier of a first fre-.

quency, a sound signal, a facsimile signal, and a subcarrier of frequency higher than but of the order of the frequency of said sound signal, modulating said subcarrier with said facsimile signal to provide a facsimile-modulated subcarrier, modulating said first carrier with said sound signal, simultaneously modulating said first carrier with said facsimile-modulated subcarrier, providing a second carrier of a second frequency and a television signal, modulating said second carrier by said television signal, and transmitting both of said carriers as modulated.

7. 1n the art of radio communication, the method of simultaneously transmitting television I signals, sound signals and facsimile signals which comprises providing a first carrier of a first freciuency, a sound signal, a facsimile signal, and a subcarrier of frequency higher than but of the order of the frequency of said sound signal, modulating said subcarrier with said facsimile signal 'to provide a facsimile-modulated subcarrier,

modulating said first carrier with said sound signal, simultaneously modulating said first carrier with said facsimile-modulated subcarrier, providing a second carrier of a second frequency and a television signal, generating synchronizing signals, synchronizing said television signal with said synchronizing signals, synchronizing said facsimile signal with said synchronizing signals,

modulating said second carrier by said television signal and said synchronizing signals, and transmitting both of said carriers as modulated.

' 8. In the art of radio communication, the method of simultaneously transmitting television signals, sound signals and facsimile signals which comprises providing a first carrier of a first frequency, a sound signal, a facsimile signal, a subcarrier of frequency-higher than but of the order of the frequency of said sound signal, and a synchronizing voltage, modulating said subcarrier with. said facsimile signal to provide a facsimile-modulated subcarrier, modulating said first carrier with said sound signal, simultaneously modulating said first carrier with said facsimilemodulated subcarrier, providing a second carrier of a second frequency and a television signal, synchronizing said synchronizing voltage with said television signal, synchronizing said synchronizing voltage with said facsimile signal, modulating said second carrier with said television signal, further modulating said second carrier with said synchronizing voltage, and transmitting both of said carriers as modulated.

'9. In systems for the transmission of sound signals, television signals and facsimile signals from respective signal generators at a transmitting station to respective signal reproducers at a receiving station, in which synchronizing signals aretransmitted from the transmitting station to the receiving station. the method which comprises transmitting the sound signals and the television signals on respectively different modulated-frequency waves, whereby the respective signals may be separated at the receiving station, transmitting the facsimile signals on a modulatedfrequency wave having a frequency substantially the same as that of the sound signal, utilizing the said synchronizing signals to synchronize the television signal generator with the. television signal reproducer, and utilizing the said synchronizing signals to synchronize the facsimile signal generator with the facsimile signal reproducer.

10. In systems for the transmission of sound signals, television signals and facsimile signals from respective signal generators at a transmit- .ting station to respective signal reproducers at a receiving station, in ,which synchronizing signals are transmittedTrom the transmitting station to the receiving station, the method which comprises transmitting the sound signals at a first carrier frequency, transmitting the television signals at a second carrier frequency, transmitting the facsimile signals at said first carrier frequency, transmitting said synchronizing signals at said second carrier frequency when said television signals are transmitted and when said facsimile signals are transmitted, utilizing the said synchronizingsignals to synchronize the television signal generator with the television signal reproducer, and utilizing the said synchronizing signals to synchronize the facsimile signal gens erator with the facsimile signal reproducer.

11. In systems for the transmission of sound signals, television signals and facsimile signals from respective' signal generators at a transmitting station to respective signal reproducers at a receiving station, in which television synchronizing signals are transmitted from the transmitting station to the receiving station, and in which the facsimile signal generator has an actuated element with which a corresponding element in the facsimile signal reproducer is desired to be synchronized, the method which comprises transmitting the sound signals at a first carrier frequency, transmitting the television signals at a second carrier frequency, transmitting the facsimile signals at said first carrier frequency, transmitting said television synchronizing signals when said television signals are transmitted and synchronizing the television signal reproducer with the television signal generator by the synchronizing signals, and transmitting said television synchronizing signals when said facsimile signals are transmitted and utilizing the synchronizing signals to maintain said actuated element of the facsimile signal generator and the said corresponding element of the facsimile signal reproducer in substantial synchronism.

12. In systems adapted for the simultaneous transmission of sound signals, television signals and facsimile signals from respective signal generators at a transmitting station to respective signal reproducers at a receiving station, in which television synchronizing signals are transmitted ,from the transmitting station to the receiving vision signals at a second carrier frequency, transmitting the facsimile signals on a sub-carrier at said first carrier frequency, said sub-carrier being substantially outside'thefrequency band of said sound signals, transmitting said television synchronizing signals when said television signals are transmitted and synchronizing the television signal reproduced with'the television signal generator by the synchronizing signals, and transmitting said television synchronizing signals when said facsimile signals are transmitted and utilizing the synchronizing signals to maintain said actuated element of the facsimile signal generator and the said corresponding element of the facsimile signal reproducer in substantial synchronism.

13. In transmitters adapted to transmit television signals and facsimile signals, the combination which comprises a generator for generating television signals, a generator for generating facsimile signals including an actuated element with which a corresponding element at a facsimile receiver is desired to be synchronized, a single source of synchronizing signals adapted to supply television synchronizing signals for said television signal generator, means for transmitting television signals and associated synchronizing signals from said source on a first carrier, means for utilizing synchronizing signals supplied from said source to maintain a synchronous relationship between the synchronizing signals and the said actuatedelement, and means for transmitting said facsimile signals on a second carrier and associated synchronizing signals from said source on said first carrier. n

14. In systems for the transmission, of sound signals, television signals and facsimile signals from a transmitting station to a receiving station, the combination which comprises a sound signal generator and means for transmitting signals generated thereby from said transmitting station to said receiving station ata first carrier frequency, a sound signal reproducer for reproducing said sound signals at said receiving station, a

television signal generator and means for tIaIiS-r' mitting television signals generated thereby 'from said transmitting station to said receiving station at a second carrier frequency, a television signal reproducer for reproducing said television signals at said receiving station, a facsimile signal generator and means for transmitting facsimile signals generated thereby from said transmitting station to said receiving station at said first carrier-frequency, a facsimile signal reproducer for reproducing said facsimile signals at said receiving station, said facsimile signal generator and facsimile signal reproducer having respective actuated elements which it is desired to maintain in synchronism, a source of synchronizing signals at said transmitting station and means for transmitting said synchronizing signals to said receiving station at said second carrier frequency, means for utilizing said synchronizing signals to synchronize the television signal reproducer with the teleyision signal generator, and means for utilizing said synchronizing signals to synchronize said actuated elements of the facsimile signal generator and facsimile signal reproducer.

15. In systems for the transmission of sound signals, television signals and facsimile signals from a transmitting station to a receiving station, the combination which comprises a sound signal generator and means for transmitting sound signals generated thereby from said transmitting station to said receiving station at a first carrier frequency, a sound signal reproduced for reproducing said sound signals at said receiving station, a television signal generator and means for transmitting television signals generated thereby from said transmitting station to said receiving station at a second carrier frequency, a television signal reproducer for reproducing said television signals at said receiving station, a facsimile signal generator and means for transmitting facsimile signals generated thereby from said transmitting station to said receiving station on a subcarrier at said first carrier frequency, said subcarrier as modulated being substantially outside of the frequency band of the sound signals, a'facsimile signal reproducer for reproducing said facsimile signals at said receiving station, said facsimile signal generator and facsimile signal reproducer having respective actuated elements which it is desired to maintain in synchronism, a source of synchronizing signals at said transmitting station and means for transmitting said synchronizing signals to said receiving station at said second carrier frequency, means for utilizing said synchronizing signals to synchronize the television signal reproducer with the television signal generator, and means for utilizing said synchronizing signals to synchronize said actuated elements of the facsimile signal generator and facsimile signal reproducer.

. PETER C. GOLDMARK. 

